This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-080874, filed Mar. 22, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to a medical instrument holding apparatus for holding a medical instrument such as an endoscope or a treatment tool, etc. when executing a treatment using a microscope.
In recent years, micro-surgery using a surgical microscope is often being executed in cranial nerve surgery. The observation range of the surgical microscope is limited to a range within which observation is executed through an incised portion of a braincase. In other words, there is an area (blind spot) that cannot be observed by the surgical microscope. When observing such a blind spot, an endoscope is used.
The endoscope is used while it is fixed and supported by a medical instrument holding apparatus having a plurality of arm joints. While observing an image through the endoscope, a treatment tool is inserted into a to-be-treated portion in a braincase, thereby executing an operation.
Since, in the braincase, various kinds of important fine tissue are intertwined in a complicated and delicate manner, the aforementioned holding apparatus is required to enable the endoscope to move smoothly and delicately without injuring the tissue, or enable it to be fixed in an accurate portion.
Jpn. Pat. Appln. KOKAI Publication No. 7-289563 discloses a medical instrument holding apparatus, which has a counterbalance mechanism for offsetting the weight of a medical instrument such as an endoscope, thereby enabling a held medical instrument to move smoothly.
Further, Jpn. Pat. Appln. KOKAI Publication No. 8-52158 discloses a medical instrument holding apparatus, in which a pair of spherical surface elements are provided at the joint of each arm section, thereby enabling the arm section to crawl around.
Since, in cranial nerve surgery, a treatment is executed while observing a surgical microscope as aforementioned, it is important that the arm section of the medical instrument holding apparatus does not interrupt the field of vision or the operation of the instrument by the doctor. Moreover, there is a case where the endoscope is inserted into, for example, a tumor in the pituitary gland of a patient through the nose. In this case, the arm section must be positioned above the patient.
In the case of the medical instrument holding apparatus disclosed in Jpn. Pat. Appln. KOKAI Publication No. 7-289563, a medical instrument held by it is enabled to be tilted about three axes of rotation, i.e. tilted with three degrees of freedom, and to be three-dimensionally positioned with three degrees of freedom by pivoting or rotating operations about three axes of rotation.
Therefore, in this case, once fixing the installation position of the holding apparatus and the position of the distal end of the endoscope, the arm section of the holding apparatus situated between the installation position and the endoscope is fixed in position and cannot be moved to an appropriate position that matches the conditions of a surgical operation. Furthermore, it is possible that the arm section interrupts the field of vision of the surgical microscope or the doctor""s operation of the instrument.
On the other hand, in the medical instrument holding apparatus disclosed in Jpn. Pat. Appln. KOKAI Publication No. 8-52158, the arm section can be situated in a most appropriate position since a pair of spherical surface elements are provided at the joint of each arm section.
However, this apparatus does not have any balancing function for offsetting the weight of an endoscope, and therefore the endoscope cannot easily be moved.
The present invention has been developed in light of the above-described circumstances, and aims to provide a medical instrument holding apparatus applicable to various types of medical instruments, and capable of selecting the holding position and angle of each medical instrument without interrupting the field of vision of its surgical microscope and the operation of the instrument.
The present invention also aims to provide a compact and lightweight medical instrument holding apparatus.
According to an aspect of the invention, there is provided a medical instrument holding apparatus comprising:
an installation section to be supported by a member in an operation room;
a support arm supported by the installation section such that the support arm is rotatable about a first axis of rotation;
a first arm supported by the support arm such that the first arm is rotatable about a second axis of rotation perpendicular to the first axis of rotation;
a second arm supported by the first arm such that the second arm is rotatable about a third axis of rotation perpendicular to the second axis of rotation;
a third arm supported by the second arm such that the third arm is rotatable about a fourth axis of rotation perpendicular to the third axis of rotation;
a holding section tilting/rotating mechanism supported by a front end portion of the third arm;
a medical instrument holding section supported by the holding section tilting/rotating mechanism such that the medical instrument holding section is tiltable and rotatable, the medical instrument holding section being designed to hold a medical instrument;
first, second, third and fourth locking units for locking the support arm, the first arm, the second arm and the third arm rotating about the first axis of rotation, the second axis of rotation, the third axis of rotation and the fourth axis of rotation, respectively, and for releasing locked states of the support arm, the first arm, the second arm and the third arm; and
a control unit capable of controlling a selected one of the first, second, third and fourth locking units.
The holding apparatus constructed as above can easily select a medical-instrument-holding position appropriate to any surgical operation. When the holding apparatus has selected an operation for enabling the arms to be moved with three degrees of freedom, a medical instrument held by the holding section can be moved. After that, when all the first, second, third and fourth locking units have been released using selection means, the holding apparatus has four degrees of freedom, whereby the positions of the arms can be moved without changing the position of the holding section and the position of the front end of the medical instrument.
Preferably, the medical instrument holding apparatus has an operation switching unit for switching an operation of the control unit between control for causing predetermined three of the first, second, third and fourth locking units to execute a locking operation, and control for causing all the first, second, third and fourth locking units to execute a locking operation.
Accordingly, the positions of the arms can be easily moved without changing the position of the holding section and the position of the front end of the medical instrument.
According to another aspect of the invention, there is provided a medical instrument holding apparatus comprising:
an arm unit including a plurality of arm members supported such that the arm members are rotatable about their respective axes of rotation;
locking units for locking the respective arm members of the arm unit about their respective axes, and for releasing a locked state of the arm members, the locking units each having a support shaft arranged coaxially with a corresponding one of the axes, a coiled elastic member mounted on the support shaft, and a deforming unit for deforming and enlarging a diameter of the coiled elastic member, the diameter of the coiled elastic member being smaller than an outer diameter of the support shaft when the coiled elastic member is in a natural state; and
a medical instrument holding section supported by one of the arm members for holding a medical instrument.
In this structure, the fastening force of each elastic member can stop a corresponding arm rotating about its axis. This structure enables the locking mechanism and hence the holding apparatus itself to be made compact and lightweight.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.